Properly maintained gear pumps require volumetric metering and stream-to-stream accuracy throughout the life of the pump. Also, in order to ensure that the precision of the pump is established upon installation, and reestablished after routine maintenance, it is necessary to test the pumps prior to installation and after any maintenance. Traditionally, many fiber producers have custom-designed their own testers, or foregone testing altogether and relied upon their service technicians' expertise and their own testers. It is believed that most of these testers have utilized the "collect and weigh" method, where the output of the pump is collected for a period of time, and then compared to theoretical values to determine the efficiency of the pump. These testers, besides being messy and allowing contaminants into the test oil, require manual weighing, conversion from weight to volume based upon specific gravity at temperature, and calculation/recording of test results.
It is believed there is a demand for a fully-contained method of measuring volumetric accuracy which requires no weighing of output result, weight conversions, or manual recording/calculations, and eliminates mess and risk of contamination.